commit https://github.com/vim/vim/commit/ac105ed3c420660ddbddc501c97875c48220817e Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jul 21 20:33:32 2016 +0200 patch 7.4.2086 Problem: Using the system default encoding makes tests unpredictable. Solution: Always use utf-8 or latin1 in the new style tests. Remove setting encoding and scriptencoding where it is not needed.

" Tests for :undo

func Test_ex_undo()
  new ex-undo
  setlocal ul=10
  exe "normal ione\n\<Esc>"
  setlocal ul=10
  exe "normal itwo\n\<Esc>"
  setlocal ul=10
  exe "normal ithree\n\<Esc>"
  call assert_equal(4, line('$'))
  undo
  call assert_equal(3, line('$'))
  undo 1
  call assert_equal(2, line('$'))
  undo 0
  call assert_equal(1, line('$'))
  quit!
endfunc